Serosorting 'not uncommon' amongst gay and bisexual men in California

The overwhelming majority of gay and bisexual men in California are aware of their own and their partner’s HIV status and many men choose to have unprotected anal sex with both primary and casual partners of the same HIV status, according to a study published in the October 24^th edition of AIDS. The investigators recommend that recent studies showing an increase the prevalence of unprotected sex and the incidence of sexually transmitted infections should be interpreted in light of these findings and suggest that unprotected anal sex need not always imply that an individual is risking infection with, or transmission of, HIV.

A quarter of a century after the first cases of AIDS were reported in gay men in California and New York, gay and bisexual men remain one of the groups most affected by HIV in the United States and other industrialised countries.

Although disclosure of HIV status as an HIV prevention tool remains a controversial subject, it is thought to have some advantages, such as acting as an incentive to use condoms, or avoid riskier sexual practices such as penetrative sex. Disclosure can also facilitate “serosorting”: the selection of sexual partners who have the same HIV status for unprotected anal sex.

Disclosing HIV status to potential sexual partners can, however, be fraught be difficulties, involving as it does the risk of rejection, stigmatisation, loss of confidentiality, or even a risk of physical violence. Well developed emotional and communication skills are therefore needed to facilitate HIV disclosure. There are also concerns that serosorting after disclosure may be an imperfect tool for HIV prevention, as individuals who believe themselves to be HIV-negative may, in fact, be infected with HIV. In addition, serosorting has been implicated in clusters of sexually transmitted infections in HIV-positive men.

Studies looking at disclosure of HIV status and resulting sexual behaviour amongst gay and bisexual men have largely been based on convenience samples and therefore might not be representative of gay and bisexual men generally. Investigators in California therefore took advantage of a state-wide telephone health survey involving 50,000 individuals that was conducted in 2001 which asked individuals about their sexual orientation. Men who self-identified as gay or bisexual were contacted in 2002 and asked to participate in a study designed to see how many men engaged in serosorting behaviours.

A total of 398 men were included in the study. The men were asked to provide demographic information and if they had a primary partner (defined as a man who they loved or felt a special commitment to), and/or secondary or casual partners (defined as men who they did not love or feel a special commitment to). The men were asked their own HIV status was, and that of their primary and most recent secondary partners. They were also asked if they had had unprotected anal sex with partners of the same, different, or unknown HIV status. Information on injecting drug use history was also requested.

The age of the participants ranged from 19 to 65 years. The majority (69%) were white, 17% had a post-graduate degree, and a fifth had an annual income of $80,000 or above. Injection drug use was reported by 7% of men. The overwhelming majority of men were aware of their HIV status, with 16% reporting that they were HIV-positive, and 78% reporting that they were HIV-negative. The remaining 6% of men did not know if they were HIV-positive or HIV-negative.

Of the 220 men with primary partners, 93% knew their own HIV status and 86% knew what their primary partner’s HIV status was.

A total of 250 men reported having secondary partners, and once again, 93% of these men knew what their HIV status was and approximately two-thirds reported knowing what the HIV status was of their recent secondary or casual partners.

HIV-positive men were more likely than HIV-negative men to have sex with HIV-positive partners. Similarly, HIV-negative men tended to have sex with other HIV-negative men. Specifically, over a third of HIV-positive men reported that their primary partner was HIV-positive, but only 7% of HIV-negative men reported having an HIV-positive primary partner (p

The investigators then looked at the men’s sexual behaviour. They found that 40% of HIV-positive men with a primary partner who was also HIV-positive, reported unprotected anal sex with this partner, behaviour the investigators defined as serosorting. However, 17% of men with an HIV-negative primary partner reported unprotected anal sex with this partner and approximately a third of HIV-positive men with a primary partner of unknown HIV status said that they had unprotected anal sex with this partner.

When the investigators looked at the answers obtained from HIV-negative men with HIV-positive primary partners, they found that 15% reported having unprotected anal sex with this partner. When HIV-negative men reported having an HIV-negative primary partner, 68% reported unprotected anal sex with this partner.

Answers regarding sex with secondary partners were then analysed. A third of HIV-positive men reported unprotected anal sex with other HIV-positive men, and 8% reported having unprotected anal sex with men who they knew to be HIV-negative.

None of the HIV-negative men reported unprotected anal sex with an HIV-positive secondary partner, but 20% reported unprotected sex with a secondary partner who they knew to be HIV-negative.

“We found that serosorting was not particularly an uncommon practice in this population,” write the investigators. They note, however that serosorting was not without its risks as one man who believed he was HIV-negative tested HIV-positive and had been having unprotected sex with his HIV-negative partner, potentially exposing him to HIV.

Nevertheless, the investigators conclude that the men in their study had a high level of knowledge about their own and their partner’s HIV status and that serosorting, particularly with primary partners was not uncommon.